Bob, who buys gold.
I'm a chemist who has refined and set up refineries to refine large quantities of gold. Part of me is saying yeah everyone should be able to refine their gold, but of late (the last 3 years or so) the jewelery related refiners have to make some important decisions before refining their own gold. In today's economy selling gold isn't all that easy as it was when alot of jewelery was manufactured in the US. As a result, unless you're independently wealthy, you will have to sell your gold.
When you use an outside refiner, they pay you for your gold, and you have more cash to buy more scrap. I have noticed a general fear of refiners on this forum. As a result I posted a few posts in the section "selling your gold" in a thread called "I've been screwed by 2 refiners "
Those posts will tell you what to look for to get a fair return from your scrap.
Now if you have a strong hankering for getting your hands into some chemicals, I would set up a small assay lab to do fire assays for gold and silver. I'd be happy to detail the setup of a small assay lab and the techniques needed. IMHO I would set up an assay lab, and a small gas fired melter to make my own bars, bring them to a refiner to witness their sampling. The refiner will assume the expense of refining and probably charge you around 2% and possibly a melt or assay fee. For his efforts, he will spend about 1/2% on the refining and stands to profit 1 1/2%. In todays market, gold can drop that profit margin in an hours trading so todays refiners take the risk which I personally would avoid. Unless you can sell all of the fine gold you can make.
These recommendations are based on an assumption that you're selling a kilo or more of scrap per trip to the refiner.
In the event that you feel my advice is not what you wanted to hear, I can also detail for you how to set up a small refinery but as I said, between selling your gold, refining the gold, treating the waste and all involved, I'd op to send my refining out.